YAG LASER FROM 808nm DIODE LASER SOURCE ...

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Abstract of thesis presented to the Senate of Universiti Putra Malaysia, in fulfilment of the requirement for the degree of Master of Science DESIGN AND DEVELOPMENT OF 1064nm Nd:YAG LASER FROM 808nm DIODE LASER SOURCE By MOHAMMADREZA SHOKRANI May 2009 Chairman: Samsul Bahari B. Mohd. Noor, PhD Faculty of Engineering Laser technology plays a crucial role in our every day life; in fact, it opens to us new windows and interesting horizon of science. In this respect, Nd:YAG is a crystal which is used as a lasing medium for solid-state lasers. Nd:YAG lasers typically emit light with a wavelength of 1064 nm in the infrared. However, there are also transitions near 940, 1120, 1320, and 1440 nm. Nd:YAG lasers operate in both pulsed and continuous mode. In this master thesis project, a solid-state Nd:YAG laser using diode laser source was built. The project consisted of two parts. The first part is based on a mathematical simulation using a MATLAB modelling. The target of this simulation was to determine graphs for the particles population in multiple gain media like the four-layer Nd:YAG laser, and some environmental coefficients were also incorporated in this modelling. The differential equations describe the 111
population of electrons in the according energy level of the Nd:YAG. They also show the output intensity of the laser. The obtained graphs described the population inversion in the energy levels inside of the Nd:YAG. The characteristics of the intensity output of the laser, during the transient time, can not be monitored by the experimental setup, therefore this was done through the MATLAB simulation. In the second part, a CW diode-pumped solid-state laser was constructed. As a laser gain medium, a Nd:YAG crystal with 1% Nd doped, lased at 1064nm, was used. 1 Watt L808P1WJ diode laser, with thermoelectric cooler, was used to excite the Nd-YAG rod. The Nd:YAG is still very inefficient in the conversion of input energy, typically the Nd:YAG lasers which are found to achieve only 5 to 10% efficiency. Light from the pump laser is generated by the laser diode driver (thorlab PRO 800- with LOC & TEC). The dimension of the Nd-YAG was 5mm diameter x 5mm length, while the mirror property of HT>99.9% @ 808nm and R>95 @ 1064nm was used. The Monochromator was used to detect the output wavelength of the laser produced. An electrical efficiency of 10.67 % was realized. The optical to optical efficiency is 19.2, with the slope efficiency of 20.2%. Although the optical to optical efficiency and slope efficiency were rather low, the electrical efficiency was considerable. IV
Page 1 and 2: UNIVERSITI PUTRA MALAYSIA DESIGN AN
Page 3: DEDICATION I dedicate this disserta
Page 7 and 8: media empat lapisan Hd:YAG laser da
Page 9 and 10: I certify that a Thesis Examination
Page 11 and 12: DECLARATION I declare that the thes
Page 13 and 14: 4 5 REFERENCES APPENDICES BIODATA O
Page 15 and 16: LIST OF FIGURES Figure Page 1.1 (A)
Page 17 and 18: 4.8 The laser output power in relat
Page 19 and 20: populated than the higher energy st
Page 21 and 22: An atom absorbs a photon (A), which
Page 23 and 24: It is important to note that using
Page 25: The amplification should arise from

YAG LASER FROM 808nm DIODE LASER SOURCE ...

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